West Pacific/2015/10W/Archive/1
Public advisory TROPICAL STORM LINFA SPECIAL PUBLIC ADVISORY NUMBER 1 WIKI-HURRICANES FORECASTING CENTER 1:15 PM JST THU JUL 2 2015 ...TROPICAL STORM LINFA FORMS IN THE WEST PACIFIC... ...FUTURE UNCLEAR... SUMMARY OF 1:15 PM JST...04:15 UTC...INFORMATION ----------------------------------------------------------------- LOCATION 14.1N 129.3E CENTER POSITION CONFIDENCE: LOW ABOUT 560 MI...900 KM E OF MANILA, PHILIPPINES MAXIMUM SUSTAINED WINDS...35 KT...40 MPH...65 KM/H MINIMUM BAROMETRIC PRESSURE...1002 MB...29.59 INCHES PRESENT MOVEMENT...NW AT 6 KT...7 MPH...11 KM/H DISCUSSION AND 48-HOUR OUTLOOK --------------------------------------------- At 1:15 pm JST, the center of newly-designated Tropical Storm Linfa was located at 14.1N 129.3E, about 560 miles (900 km) east of Manila, Philippines. Maximum sustained winds were 35 knots (40 mph, 65 km/h), with higher gusts. The minimum barometric pressure was 1002 mb (29.59 inHg), and the cyclone was moving steadily northwestward at 6 knots (7 mph, 11 km/h). Environmental conditions are expected to favor slow to strengthening over the next few days, but they may become less conducive by the end of the forecast period. NEXT ADVISORY ------------------- Next complete advisory at 6:00 pm JST. $$ Forecaster TAWX14 Discussion TROPICAL STORM LINFA SPECIAL DISCUSSION NUMBER 1 WIKI-HURRICANES FORECASTING CENTER 1:15 PM JST THU JUL 2 2015 Visible satellite animations indicate that the area of low pressure located a few hundred miles east of the central Philippines has organized over the past 24 hours, and advisories are being initiated on a tropical cyclone at this time. The system is not well organized in the truest sense, with an irregular convective mass offset from an elongated low-level circulation. Although recent satellite intensity estimates were T1.0/25kt from both JTWC and SAB, as well as T1.7/27kt from UW-CIMSS ADT, a 2201z Rapidscat pass indicated a small area of 35kt winds within the southwestern quadrant of the cyclone, and that value is being set as the initial intensity at this time. Tropical Storm Linfa is the 10th named storm of this active 2015 Pacific typhoon season. The initial motion is steadily northwestward this evening. Linfa is being steered on this course via the western extent of a mid-level ridge across the northern West Pacific. This steering regime is expected to continue to be the dominant steering mechanism throughout the forecast period. However, complicating matters is the forecast progression of an upper-level trough across mainland China and across Japan after 72 hours. The GFS and ECMWF agree on how much influence this trough will have on Linfa, with the former showing a weaker trough and subsequent slower/more west track and the latter showing a stronger trough and subsequent faster/more east track. The track forecast for this advisory cycle is essentially a blend of the two. The environment Linfa finds itself in is generally favorable for slow intensification, with sea surface temperatures near 30C, high ocean heat content values, and a generally moist mid-level atmosphere. However, one potential limiting factor is a moderate 10 to 20 knots of easterly wind shear, which is not expected to relent over the next few days. As such, global and hurricane models only show slow intensification, and the intensity forecast this cycle will follow suit. By the end of the forecast period, interaction with the northern Philippines as well as increasing shear may cause Linfa to begin weakening, although the GFS and ECMWF disagree on the extent of such weakening. INIT 02/0415Z 14.1N 129.3E 35 KT 40 MPH 12H 02/1200Z 14.7N 128.9E 35 KT 40 MPH 24H 03/0000Z 15.2N 128.0E 40 KT 45 MPH 36H 03/1200Z 15.6N 127.1E 45 KT 50 MPH 48H 04/0000Z 16.1N 125.9E 50 KT 60 MPH 72H 05/0000Z 16.6N 125.2E 55 KT 65 MPH 96H 06/0000Z 17.3N 124.0E 50 KT 60 MPH 120H 07/0000Z 18.2N 122.8E 45 KT 50 MPH $$ Forecaster TAWX14